The expense of certain types of materials processing equipment resources can render such resources economically difficult to justify for smaller organizations, and, as such, may leave a manufacturer with no choice but to employ more traditional and less productive methods. One solution, however, is to share more costly resources among several operators or work areas, thereby permitting greater utilization of such equipment and enhancing the financial aspects of the overall system through shorter payback periods. Such resource sharing also permits improved productivity, reduced component fabrication cost, an ability to process a greater variety of components simultaneously, and a more flexible system, better able to meet changing schedules. Overall, in many circumstances, sharing of costly resources may lead to a more competitive position in desired marketplaces.
In recent years, significant progress has been made in the application of lasers to materials processing. This progress has been two-fold, through developments in higher-power laser sources and, additionally, through more innovative approaches to beam-delivery problems. Efficient beam delivery, which is crucial to any industrial laser processing application, has been improved through the introduction of low-loss industrial-type optical fibers which, in turn, have introduced new system design possibilities. These novel fiber-based beam-delivery techniques are capable of reducing system cost and, consequently, such approaches may directly affect the economics of laser-based materials processing.
One advantage of fiber-based beam-delivery in the realm of materials processing is its adaptability to modern flexible-manufacturing techniques. Time multiplexing and energy multiplexing may be carried out with fiber-based beam delivery in a relatively straightforward conceptual manner, with distributed computer control being applied to realize full system potential. An optimal configuration would include an architecture and interfaces to provide real-time control over various laser functions while supporting necessary communication between work areas and factory-information systems.
As it happens, however, the sharing of multiple resources among multiple work areas demands much more than a straightforward interconnection scheme and time multiplexing. To achieve desired computer control and coordination of activities associated with all system elements, a complex communication and control structure must necessarily be imposed with hardware and software exhibiting the bandwidth and response time required for efficient operation at all system levels. In some cases, distributed communication via local-area network may be appropriate, whereas direct, real-time digital input/output may be necessary between the hardware resources and the tools which benefit from those resources.
With specific regard to laser-based processing, once energy is directed to a particular work area by selecting the proper output fiber, the equipment controller must be able to assume control of the laser, including the ability to fire the laser quickly, with a circuit delay time between the request and the actual time at which the laser fires of milliseconds or less. This is practically impossible in conventional hierarchically designed process control systems, wherein instructions must be distributed and interpreted at multiple levels before control of resources may be relinquished or assumed. The required signaling speed may be achieved by direct hardware connection of digital control between equipment controllers and lasers, but with multiple resources and work areas demanding those resources, contention between competing control signals must be properly arbitrated.